% -------------------------------------------------------------------------
% 火箭方程
%
% Copyright(C) 2016/09/29 by Chen Zhang,
% Tsinghua Space Center
% chenzhang.buaa@gmail.com
% -------------------------------------------------------------------------
function mf = rocketEquation(dv , aux)

if nargin == 1
    g0 = 9.80665 * 1e-3; % gravitational constant, kg*km/s^2
    Isp = 300; % s
    c = Isp * g0; % exhaust velocity, kg*km/s
end

m0 = 1;
mf = m0 * exp(-dv / c);

end
